Ship propulsion system



Dec. 26, 1939. c. T. BUFF SHIP PROPULSION SYSTEM Filed July 13, 1938 3 Sheets-Sheet l H J QN JMH A m \QM, Q N 3 N mm mm T an Nd r .6 wjwm mm, Q

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INVENTOR C0r/777e0d0rBu/f.

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ATTORNEY Dec. 26,1939. c. T. BUFF 2,184,764

SHIP PROPULSION SYSTEM Filed July l5, 1958 3 Sheets-Sheet 2 WITN ESSES: I INVENTOR (5, CO/T/ 7l;/Y700orBu ATTORNEY Dec. 26, 1939. c. T. BUFF 2,184,764

SHIP PROPULSION SYSTEM Filed July 15, 1938 s Sheets-Sheet s fjga.

WITNESSES:

\ INVENTOR (2 a 7% Car/ 777e0o rBu 2 QZWQ M W ATTORNEY Patented Dec. 26, 1939 UNiTED STATES SHIP PROPULSION SYSTEM' Carl Theodor Buff, Berlin-Charlottenburg, Germany, assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania.

Application July 13, 1938, Serial'No. 219,043 r In Germany July 17, 1937 8 Claims. (01. -37.)

My invention relates to a ship propulsion system for a multiple screw, or multiple propeller drive.

Ship propulsion systems, in which a plurality of propellers are mechanically coupled. to a like number of steam engines, are well known. It is also Well known to use the exhaust steam from such steam engines in exhaust turbines, which turbines are also coupled to the propellers to aid in driving the propellers. For many such installations, an electric energy transmitting scheme is used in which the exhaust turbine drives a generator which feeds an electric motor connected with the associated shaft. If such a known drive is used for a twin screw ship, diffi- 'culties arise in the operation of the ship. If, for example, one of the steam engines serving the direct drive is not in use, operation with one ship propeller only may take place, with the result that the course of the ship is difficult to maintain by reason of the one-sided propeller thrust'and,

what is equally as bad, the drive does not operate economically.

One object of my invention is to improve the steering characteristics of a ship using two or more propellers.

Another object of my invention is. to eliminate all the diiiculties experienced with the type of known drive hereinbefore discussed.

My invention relates to a ship drive with at least two propellers, in which drive each propeller is mechanically coupled to a steam engine and an electric motor which is fed by a generator driven by an exhaust turbine fed by the exhaust of one of the steam engines. To suppress the difiiculties hereinbeiore mentioned, which may arise on outage of any one of the individual parts of the plant, and further, for reasons of economy, to be able to set at rest any individual part of the main drive for definite driving speeds, selective switching devices are provided in accordance with the invention. By the operation of such selective switching means, it is possible to permit the generator to act on any propeller motor selected, or, under certain'circumstanoes, also to supply energy to a plurality of propeller motors simultaneously.

The invention may also be applied in ship propulsion systems in which the auxiliary motors, coupled .with the propeller shafts, are fed from a single generator which is driven by an exhaust turbine fed with exhaust steam from both main steam engines.

When ship drives are involved invvhich there are generators driven by one or more exhaust the propeller loadremains uniform, the ship may turbines, I use switching devices,-by the operation of which it is possibleto permit one or more of these generators to selectively operate on one 7 or more propeller motors selectable at will.

In using my invention, a ship drive is not im- 5 paired and remains reliable, economical, and at a high efficiency in spite of the outage of one or more of the individual machines. Also it is pos-v sible for economic reasons to selectively set at' rest individual main driving engines, for exampie, on outage of'one ofthe main driving machines, bo-th ship propellers may be kept in op; eration. This is preferably carried out in-such manner that the motor, coupled to the particular propellershaft whose steam engine is' out of 5 service, is electrically connected to the generator driven from the exhaust steam turbine of an engine still in service;- The other propeller shaft, coupled to the engine still in service, is then preferably driven only by that main steam engine, whereas the Whole energy of the exhaust turbine, in service, is supplied to the propeller motor, the associated steam machine of which is out of service. In case of breakdown of an exhaust steam turbine, of a enerator, or of agear drive, 5

the associated propellers may be supplied each with half oithe energy of the turbo-generators still in operation. Since, under this condition,

be well controlled and the ship drive in spite of 0 the breakdown operates, as far as possible, economically. I i

From the brief descriptionhereinbefore given and theobjects in part stated, it is apparent that one of the broad objects of my invention; is the provision of the combination of a mechanical and electrical drive for a ship having two or more propellers. r

A still further object of my invention is the provision, in a ship propulsion system, of a plu-" rality of steam engines mechanically coupled to a like number of ship propellers, one or'more exhaust turbines supplied from the exhaust steam of any one or all the steam engines, a generator coupled to each exhaust turbine, a motor on each propeller shaft and selective switching means for selectively interconnecting, said motors with said generators.

Still other objects and advantages will become more apparentv from a study ofthe following specificatiomand the accompanying drawings, in which: i v

Figure 1 is a diagrammatic showing of a twin 7 propellership drive utilizing one embodiment of my invention;

Fig. 2 is another diagrammatic showing of a twin propeller ship drive utilizing a modification of my invention; and

Fig. 3 is a schematic showing of my invention arranged to be automatic in operation.

Referring to Figure 1, the reference characters I and 2 designate the two propeller shafts to which the steam engines 3 and 4 are mechanically coupled through clutches 5 and 6. These engines 3 and 4 may be disconnected from the propeller shafts with the aid of the associated clutch couplings 5 and 0' For auxiliary propeller driving machines, electric motors 1 and 8, which may be fed from the generators 9 and I0, are coupled with the propeller shafts. The generator 9 is driven by an exhaust turbine II associated with the steam engine 3 through a drive I 3 and the generator I0 is driven by an exhaust turbine I2 through a drive I4. The exciting energy is supplied, from a direct-current ship network. I5, I6, through the switches I1, I8, I9 and 20. The numerals 2| and 22 identify the manually operable controllers which serve for field regulation of the generators 9 and I0 and motors 1 and 8. The hand wheels of these two regulators may be actuated selectively, thatis, in common, or independently of each other.

In the leads interconnecting the motors and the generators, overcurrent relays 23 and 24 are built in, which, on the selected overload, close the associated contacts 25 and 26, and thereby permit the switching relays 21 and 28 to operate so that the latter open the switches 29 and 30', respectively, in the exciting circuits of the generators, and thus introduce a complete de-excitation of the generators, or a decreased excitation of the generators depending on the operation desired. By the switching relays 21 and 28, a corresponding weakening of the motor excitation is at the same time attained by switches 29 and 30. By switches 40 and M and 42 and 43, the resistors 44 and and 46 and 41 may be placed in the field circuits of the generators and motors or taken out of these: circuits.

The reference numerals 3| and 32 respectively, identify the governor devices for the main steam engines. These governors are coupled to drive torque direction indicating means 48 and 49, to .reversing switches 33 and 34 so that as the direction of rotation of the engines is changed the excitation of the associated generators is also reversed. g

In the leads interconnecting the generators ,to the motors, switches 35, 36, 31, 38 and 39 are arranged with the aid of which it is possible to selectively permit one or both of the generators to operate on either of the two motors or on both simultaneously. In the illustrated circuit position of the switches 35, 36, 31, 38 and 39, the generator 0 operates on the motor 1 and the generator I0 on the motor 8. For the case when the main steam. engine 3 is, for one reason or another, not in service, the ship propeller shaft 2 may be driven from the main steam engine 4, and the ship propeller shaft I from the electric motor I which is then connected to the generator I0 driven by the exhaust turbine I2. In this case, the clutch 5 between the steam engine 3 and the ship propeller shaft I is released.

In case, for example, the exhaust turbine l2, the gear drive H3 or the generator I0 should not be in service, the two motors 1 and 8 may be fed in common from the generator 9 by the opening of the switch 36 and the closing of the coupling switch 39, whereby the propeller load of both screws may be maintained equal, so that again a good control possibility is present and the ship drive, in spite of the outage, may operate particularly economically.

In the modification shown in Fig. 2, I utilize a single turbine III operating from the exhaust steam of either or both of the steam engines I03 and I04. In this modification the engines I03 and I04 may be directly connected to the propeller shafts I0! and I02 by clutches I05 and I06.

Coupled to the turbine II I is an alternator I09 which is adapted to be connected to the propeller driving motors I01 and I08 through the switches I35, I31 and I38.

The excitation for the alternator as well as the motor is supplied from the direct current buses II 5 and II 9 through the switches H1, H8 and I20. The excitation is, however, modified and controlled in a well known manner by the controller I2I. Associated with a supply lead from the generator leading to either one or both of the motors I01 and I08 is an overload relay I23 which, upon the attainment of a predetermined overload is adapted to close the contact members I25 to energize the actuating coil for the field excitation controlled relay I21. When this relay I21 is energized, it is adapted to open the contact members I28, I29 and I30, which contact members may open the field circuits of both the alternator and the motors completely, or, if desired, decrease the field excitation in a desired manner. If the switches I39, I40 and I 4| are in the position shown, then the opening of the contact members I29, I28 and I30 merely alters the excitation of the alternator and the motors.

The steam engines I03 and I04 have the governors I3I and I32 associated respectively with these engines and these governors also operate torque direction indicating means I48 and I49 which are adapted to operate the switch I34 to reverse the excitation of the alternator if the direction of rotation of the engines is altered. The excitation of the motors is, however, not altered since the excitation for the motors proceeds through the controller I2I from the leads I50, I5I. The arrangement of valve I52 is, of course, such that the turbine III may be supplied with exhaust steam from either one or both of the engines I03 and I04,

In the event engine I03 is for any reason out of service, the clutch I05 is operated to disconnect the propeller shaft IOI from the engine I03 and the turbine I II is operated from the exhaust steam of engine I04. The electrical energy of the alternator I 09 is then supplied to the motor I01 only by the opening of switch I33 and the closure of switches I35 and I31. By a different arrangement of the switches I35, I31 and I38, the motor I08 may be operated from the alternator I09 when engine I04 is out of service.

My invention is not limited to the manually selectable switching means. The manually selectable switching means shows the fundamental or broad idea of my invention but an automatic embodiment of my invention is generally illustrated in Fig. 3. In this embodiment, the shafts and. all other elements common to the showing in Fig. 1 are given the same reference characters.

Switching means 235 are automatically responsive to the voltage of generator 9, whereas to be connected to some suitable source of energy as buses l5 and I6.

If, for instancefeither the gen'erator 9, the gear connection 53, or the turbine II or some or all of these units are out of service, the voltage of generator IE? only builds up and switching means 236 are closed. The generator I!) supplies both motors 1 and 8 in addition to the engine torque supplied to both of the propeller shafts. If both turbines are in service, both generators build up their voltages and switching means 235 and 236 are operated. When both these switching means are thus operated, the contact members 248 and 25! are both closed with the result that switch 239 is opened. Each generator thus supplies its energy ,to one corresponding motor.

If, for example, engine 4 is out of service, clutch 6 is first opened and upon greater angular movement of the clutch actuating arm thereafter closes switch 242 which causes the opening of switch or contact members 231. Since, under this condition of operation generator 9 only builds up its voltage switching means 235 close, switching means 238 and 239 are closed and switching means 236 are open. The entire energy of generator 9 is thus supplied to motor 8 whereas engine 3 alone operates on shaft l. Ihe propeller torques are thus balanced and the maintenance of the course is facilitated. When the engine 3 is out of service clutch 5 is opened and switch 243 is closed. In consequence, generator it! supplies its entire energy to motor I.

It is, of course, apparent that an alternating current drive scheme may be combined with the arrangement of exhaust turbines and control, shown in Fig. 1, since my invention is not limited to the particular two modifications shown, but may embody alterations of both of these modifications and substitution of elements in one for elements shown in the other without departing from the scope of my invention. Applicant is also aware that others, particularly after having had the benefit of the teachings of my invention may devise other similar schemes of control for controlling a ship, and applicant, therefore, does not wish to be limited by the particular showings made but only to be limited by the scope of the claims hereto appended and such prior art as may be pertinent.

I claim as my invention:

1. In a ship propulsion system utilizing at least two propellers, in combination, a pair of steam engines, a pair of interconnecting means having a plurality of positions adapted to couple one engine to each propeller shaft, a pair of exhaust steam turbines operated, respectively, from the exhaust steam of the two engines, a motor coupled to each propeller shaft, a generator driven by each turbine, and automatically operable electromagnetic selecting switches responsive to the positions selected by said interconnecting means and the electrical characteristics of said, generators adapted to automatically connect one generator to one motor and the other generator to the other motor or one generator. to both motors.

2. In a ship propulsion system utilizing at least two propellers, in combination, a pair of steam engines, a pair of interconnecting means having a plurality of positions adapted to couple one engine to each propeller shaft, a pair of exhaust steam turbines operated, respectively, from the exhaust steam of the two engines, a motor coupled to each propeller shaft, a generator driven by each turbine, and automatically operable the positions selected by said interconnecting means and the electrical characteristics of said generators adapted to connect one generator to one motor orone generator to both motors.

3. In a ship propulsion system utilizingat least twopropellers, in combination, a pair of steam engines, a pair of interconnecting means having a plurality of positions adapted to couple one engine to each propeller shaft, a pair of exhaust steam turbines operated, respectively, from the exhaust steam of the-two engines, a motor cougine to. each propeller shaft, a pair of exhauststeam turbines operated, respectively, from the exhaust steam of the two engines, a motor coupled to each propeller shaft, a generator driven by each turbine, and automatically operable electromagnetic selecting switches adapted for one position of one of said interconnecting means to automatically connect the generator normally associated with the engine and motor and propeller at one side of the ship with the motor associated with the propeller at the other side of the ship.

5. In a ship propulsion system, 'in combination, a steam engine, a propeller shaft, a clutch for connecting the engine to the shaft and for disconnecting the engine from the shaft, electric ship propulsion means adapted to also operate the propeller shaft, and switching means actuated by the opening of said clutch adapted to connect the electric ship propulsion means to the propeller shaft to thus maintain operation of the shaft in spite of outage of the engine.

6. In a ship propulsion system, in combination, a steam engine, a propeller shaft, clutch means for connecting anddisconnecting the shaft and engine, a second engine, a second propeller shaft, clutch means for connecting and disconnecting the shaft and engine, electric ship propulsion equipment operated by each of the engines adapted to also operate the propeller shafts, and means responsive to the opening, or disconnecting, operation of one of the clutch means adapt-. ed to connect certain of said electric ship propulsion equipment to the'propeller shaft disconnected from its engine by the disconnecting operation of the clutch means.

7. In a twin propeller ship propulsion system,

in combination, a steam engine connected to one propeller, asecond steam engine connected to the other propellenan exhaust turbine operated by the engine exhaust steam, a generator driven by the turbine, a motorcoupled to one propeller, a second motor coupled to the other propeller, clutches associated with each engine and propelelectromagnetic selecting switches responsive to lershaft adapted to disconnect the engines from the propeller shafts, and means caused to operate by the operation of a clutch to disconnect an engine from a propeller adapted to cause the electric interconnection of the generator with the motor coupled to the propeller disconnected I from the engine. 8. In a ship propulsion system for a twin pro peller drive, in combination, a steam engine coupled to each propeller, a motor also coupled to each propeller, turbo-electric generating means operated from the engine exhaust steam adapted to supply electric energy to the motors, and a pair of clutches for disconnecting the engine from the respective propellers, and means, responsive to the operation of one of the clutches, adapted to connect the turbo-electric generating means to the motor coupled to the shaft that is thus disconnected from one engine by the operation of one of the clutches.

CARL THEODOR BUFF. 

